The ornamental design for a sock, as shown and described.
FIG. 1 is a left front perspective view of a sock, in accordance with this invention;
FIG. 2 is a front elevational view of the sock of FIG. 1;
FIG. 3 is a rear elevational view of the sock of FIG. 1;
FIG. 4 is a top plan view of the sock of FIG. 1;
FIG. 5 is a bottom plan view of the sock of FIG. 1;
FIG. 6 is a left side elevational view of the sock of FIG. 1; and,
FIG. 7 is a right side elevational view of the sock of FIG. 1.
The patterned (grid-profiled) part shown in the drawings illustrate different texture enhancing the aesthetic appearance of the sock of the invention. No specific color is intended by the selection of the cross-hatching in FIGS. 1 through 7.